1. Field of the Invention
This invention relates to a camera system for forming a single picture image by a composition of a plurality of image data of the same object which are taken by an image pickup device such as CCD (Charge Coupled Device).
2. Description of the Related Art
In a conventional digital camera for taking a still picture image by using an image pickup device, when a luminance of an image is lower and a flash light is not used, a charge storage time for storing electric charge in each pixel of the image pickup device (hereinafter, abbreviated as integration time) is lengthened for adjusting a brightness of an image displayed on a monitor display. Alternatively, an amplification factor for amplifying output signals from the image pickup device is increased for adjusting the brightness of the image displayed on the monitor display.
When the integration time is lengthened longer than a certain integration time (hereinafter abbreviated as limit integration time), the image focused on the image pickup device will be moved while a charge storage operation of the image pickup device due to the shaking of the operator's hand (hereinafter, abbreviated as camera shake). Thus, the image displayed on the monitor display will be blurred due to the camera shake.
On the other hand, when the amplification factor of the output signals from the image pickup device is increased, the image displayed on the monitor display includes a lot of noise component, and a quality of the image is lower. Since a quantity of the electric charge stored in each pixel of the image pickup device is originally a few, the output signal having relatively lower S/N is amplified by a larger amplification factor.